Method of abrading silicon substrate

ABSTRACT

A pressurized delivery system for abrasive particulate material includes a storage container adapted to contain the abrasive particulate material therein, an input pressure line adapted to communicate with a pressurized source, and a fluidizing pressure line communicating with the input pressure line and an inlet opening in the storage container. A back-pressure pressure line communicates with an unoccupied portion of the storage container and an output pressure line. The output pressure line, into which the abrasive particulate material is fed from the storage container, communicates with the input pressure line, the back-pressure pressure line, and an outlet opening of storage container. During operation, pressurized gas is released through the inlet opening and into the storage container such that the abrasive particulate material adjacent the outlet opening is fluidized and maintained flowable so as to achieve consistent flow of the abrasive particulate material through the outlet opening.

THE FIELD OF THE INVENTION

[0001] The present invention relates generally to a system fordelivering abrasive particulate material under pressure, and moreparticularly to a system which utilizes a pressurized source to fluidizeand deliver abrasive particulate material for abrading a surface ofanother material, such as for abrading a portion of a silicon substrateof an ink-jet printhead to thereby form an ink fill slot in the siliconsubstrate.

BACKGROUND OF THE INVENTION

[0002] A conventional process, commonly referred to as sandblasting,combines abrasive particulate material, such as sand, with a pressurizedsource of gas, for example, air, to form an abrasive mixture underpressure and directs the abrasive mixture under pressure at a surface.Such a conventional sandblasting process is typically used for cleaning,polishing, or abrading the surface at which the abrasive mixture isdirected. Existing sandblasting systems typically include a storagecontainer adapted to contain the abrasive particulate material therein,and a pressure line through which the pressurized source of gas isdirected and into which the abrasive particulate material is fed bygravity flow from the storage container.

[0003] More particularly, sandblasting has been employed to form an inkfill slot in a silicon substrate of an ink-jet printhead. Existingsandblasting systems employed for forming the ink fill slot typicallyrely on gravity flow, vibration of the storage container, and/ormodulation of the pressure line to ensure discharge of the abrasiveparticulate material from the storage container, through a meteringorifice, and into the pressure line. The vibration and/or modulation inthese existing sandblasting systems, however, results in chaoticbehavior, or inconsistent flow, of the abrasive particulate materialthrough the metering orifice. This chaotic behavior resulting when theink fill slot is formed with existing sandblasting systems is identifiedby random size and shape variations of the ink fill slot. Since the inkfill slot provides a supply of ink to a printing element of the ink-jetprinthead during a printing process, a distance from the ink fill slotto the printing element effects the supply of ink to the printingelement. Size and shape variations in the ink fill slot, therefore, candegrade printing performance.

[0004] Accordingly, a need exists for a system for delivering abrasiveparticulate material under pressure which provides consistent flow ofthe abrasive particulate material from a storage container, through ametering orifice, and into an output pressure line. In particular, thereis a need for a method for more uniformly forming an ink fill slot in asilicon substrate of an ink-jet printhead.

SUMMARY OF THE INVENTION

[0005] One aspect of the present invention provides a pressurizeddelivery system for abrasive particulate material. The pressurizeddelivery system includes a storage container adapted to contain theabrasive particulate material therein, an inlet valve communicating withan inlet opening of the storage container, and a first flow pathcommunicating with the inlet valve. A second flow path, adapted tocommunicate with a pressurized source of gas, communicates with thefirst flow path, and a third flow path communicates with the second flowpath in parallel flow with the first flow path. A fourth flow pathcommunicates with an unoccupied portion of an interior space of thestorage container, and a fifth flow path communicates with the thirdflow path, an outlet opening of the storage container, and the fourthflow path. As such, a pressurized supply of the abrasive particulatematerial may be formed and delivered through the fifth flow path.

[0006] In one embodiment, the third flow path is in parallel flow withthe first flow path from the second flow path.

[0007] In one embodiment, the abrasive particulate material includessand, aluminum oxide, silicon carbide, quartz, or diamond dust. In oneembodiment, the gas is air and in another embodiment, the gas is aninert gas for use, for example, when a material to be processed with thepressurized delivery system is sensitive to air and oxidation of thematerial is a concern.

[0008] In one embodiment, the inlet valve is a one-way valve and in oneembodiment, the one-way valve is a duckbill check valve which iseffective at creating a tight seal when closed despite communicatingwith the abrasive particulate material.

[0009] In one embodiment, an adjustable control valve is providedin-line in the first flow path before the inlet valve to set a desiredflow rate of pressurized gas supplied to the inlet valve. In oneembodiment, a first check valve is provided in-line in the second flowpath before the first flow path and the third flow path, and a secondcheck valve is provided in-line in the third flow path. In oneembodiment, a filter is provided in-line in the third flow path afterthe second check valve to help keep the abrasive particulate materialfrom back streaming into the second check valve.

[0010] In one embodiment, the fourth flow path includes an inlet orificecommunicating with the unoccupied portion of the interior space of thestorage container to restrict input to the fourth flow path.

[0011] In one embodiment, a baffle is positioned within the storagecontainer above the inlet opening to disperse pressurized gas releasedinto the interior space of the storage container so as to more evenlydistribute pressurized air throughout a base of the storage container.In one embodiment, a nozzle is provided at an output end of the fifthflow path for accelerating and directing the abrasive particulatematerial toward a surface to be processed.

[0012] Another aspect of the present invention provides a pressurizeddelivery system for abrasive particulate material. The pressurizeddelivery system includes an input pressure line having a first endadapted to communicate with a pressurized source of gas, a fluidizingpressure line having a first end communicating with the input pressureline, and a storage container adapted to contain the abrasiveparticulate material therein. An inlet valve communicates with a secondend of the fluidizing pressure line and an inlet opening of the storagecontainer. A back-pressure pressure line has a first end communicatingwith an unoccupied portion of an interior space of the storagecontainer, and an output pressure line has a first end communicatingwith a second end of the input pressure line, a second end of theback-pressure pressure line, and an outlet opening of the storagecontainer. As such, a pressurized supply of the abrasive particulatematerial may be formed and delivered through the output pressure line.

[0013] Another aspect of the present invention provides a method ofdelivering abrasive particulate material under pressure from a storagecontainer adapted to contain the abrasive particulate material therein.The method includes the steps of communicating an inlet valve with aninlet opening of the storage container and supplying a first gas,regulated to a first predetermined pressure, to the inlet valve. Thefirst gas is released through the inlet valve and into the storagecontainer, and a quantity of the abrasive particulate material isdischarged through an outlet opening of the storage container to anoutput junction. In addition, a second gas, regulated to a secondpredetermined pressure, is supplied to the output junction. As such, apressurized supply of the abrasive particulate material is formed anddelivered through the output junction.

[0014] Another aspect of the present invention provides a method ofabrading a portion of a silicon substrate. The method includes the stepsof fluidizing abrasive particulate material with a first gas within astorage container, combining the gas fluidized abrasive particulatematerial with a stream of a second gas to provide a stream of the gasfluidized abrasive particulate material, and directing the stream of thegas fluidized abrasive particulate material at the silicon substrate toabrade the portion of the silicon substrate.

[0015] Another aspect of the present invention provides a method offorming an ink fill slot in a silicon substrate of an ink-jet printhead.The method includes the steps of fluidizing abrasive particulatematerial with a first gas within a storage container, combining the gasfluidized abrasive particulate material with a stream of a second gas toprovide a stream of the gas fluidized abrasive particulate material, anddirecting the stream of the gas fluidized abrasive particulate materialat the silicon substrate to form the ink fill slot in the siliconsubstrate.

[0016] Another aspect of the present invention provides an ink-jetprinthead including a silicon substrate having an ink fill slot formedtherein by fluidizing abrasive particulate material with a first gaswithin a storage container, combining the gas fluidized abrasiveparticulate material with a stream of a second gas to provide a streamof the gas fluidized abrasive particulate material, and directing thestream of the gas fluidized abrasive particulate material at the siliconsubstrate to form the ink fill slot in the silicon substrate.

[0017] The present invention provides a system for delivering abrasiveparticulate material under pressure such that more accurately meteredflow of the abrasive particulate material from a storage container,through a metering orifice, and into an output pressure line isachieved. More particularly, the present invention provides a method formore uniformly forming an ink fill slot in a silicon substrate of anink-jet printhead.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a schematic view of a pressurized delivery system forabrasive particulate material according to the present invention;

[0019]FIG. 2 is an enlarged view of a portion of FIG. 1 illustratingportions of the pressurized delivery system including an inlet valve inan opened state;

[0020]FIG. 3 is an enlarged view of a portion of FIG. 1 illustratingportions of the pressurized delivery system including an inlet valve ina closed state;

[0021]FIG. 4 is a perspective view of a portion of an ink-jet printheadincluding an ink fill slot formed in a silicon substrate by apressurized delivery system according to the present invention;

[0022]FIG. 5 is a top view of a portion of an ink-jet printheadincluding a plurality of printing elements formed on a silicon substrateand an ink fill slot formed in the silicon substrate by a pressurizeddelivery system according to the present invention; and

[0023]FIG. 6 is a cross-sectional view of an ink fill slot formed in asilicon substrate by a pressurized delivery system according to thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] In the following detailed description of the preferredembodiments, reference is made to the accompanying drawings which form apart hereof, and in which is shown by way of illustration specificembodiments in which the invention may be practiced. It is to beunderstood that other embodiments may be utilized and structural orlogical changes may be made without departing from the scope of thepresent invention. The following detailed description, therefore, is notto be taken in a limiting sense, and the scope of the present inventionis defined by the appended claims.

[0025]FIG. 1 illustrates one embodiment of a pressurized delivery system10 for abrasive particulate material 12 according to the presentinvention. Pressurized delivery system 10 includes a storage container20, an input pressure line 30, a fluidizing pressure line 40, an inletvalve 50, a back-pressure pressure line 60, and an output pressure line70. Storage container 20 defines an interior space 22 adapted to containabrasive particulate material 12 therein. When abrasive particulatematerial 12 is deposited within storage container 20, an occupiedportion 22 a and unoccupied portion 22 b of interior space 22 aredefined. Unoccupied portion 22 b includes a portion of interior space 22devoid of abrasive particulate material 12. Abrasive particulatematerial 12 may include sand, aluminum oxide, silicon carbide, quartz,diamond dust, or any other suitable abrasive material in particulateform or particulate material having suitable abrasive qualities for adesired application of pressurized delivery system 10.

[0026] In one embodiment, storage container 20 is generally cylindricalin shape and includes a base 24 having an inlet opening 26 and an outletopening 28 defined therein. Outlet opening 28 functions as a meteringorifice through which abrasive particulate material 12 is fed to outputpressure line 70. In one embodiment, inlet opening 26 is adjacent tooutlet opening 28 and a baffle 25 is provided above inlet opening 26. Inaddition, base 24 of storage container 20 includes a bottom wall 24 a,in which inlet opening 26 and outlet opening 28 are formed, and aninwardly, downwardly sloping side wall 24 b. Inwardly, downwardlysloping side wall 24 b facilitates gravity flow of abrasive particulatematerial 12 downward within storage container 20 toward outlet opening28.

[0027] Input pressure line 30 has a first end 32 and a second end 34.First end 32 of input pressure line 30 is adapted to communicate with apressurized source of gas 14. Second end 34 of input pressure line 30communicates with an output junction 76 of output pressure line 70. Inone embodiment, the gas is air delivered by a pressure regulating system16. In an alternate embodiment, the gas includes an inert gas, such asargon. Use of inert gas may be preferred, for example, when a materialto be processed with pressurized delivery system 10 is sensitive to airand oxidation of the material is a concern. For clarity, the followingdescription only refers to using pressurized air, but it is understoodthat use of other gases, or combinations of gases, is within the scopeof the present invention.

[0028] In one embodiment, a series of check valves are provided in inputpressure line 30. The check valves include a low-pressure check valve 37and a resister check valve 38. In addition, a filter 39 is providedin-line in input pressure line 30 after resister check valve 38. Filter39 helps keep abrasive particulate material 12 from back streaming intoresister check valve 38. An example of such a filter is a 9071-20-1/8,25 micron filter manufactured by Arrow.

[0029] Low-pressure check valve 37 is provided in-line in input pressureline 30 to prevent back flow from storage container 20 into pressureregulating system 16 if a pressure drop occurs. Low-pressure check valve37 has a low cracking pressure, for example, ⅓ pounds per square inch(psi), to reduce overall pressure drop in the system. An example of sucha check valve is a SS-6C-1/3 check valve manufactured by Nupro. Resistercheck valve 38 is provided in-line in input pressure line 30 afterlow-pressure check valve 37. Resister check valve 38 produces a fairlyconstant pressure drop equal to its cracking pressure, for example, 10psi. An example of such a check valve is a 4M-C4L-10-B check valvemanufactured by Parker.

[0030] Resister check valve 38 develops a pressure in both inputpressure line 30, between low-pressure check valve 37 and resister checkvalve 38, and fluidizing pressure line 40 which is higher than apressure in input pressure line 30 after resister check valve 38. Assuch, a higher regulated pressure is developed before resister checkvalve 38 and a lower regulated pressure is developed after resistercheck valve 38. This higher pressure, before resister check valve 38,produces a drive pressure for fluidizing pressure line 40. A benefit ofresister check valve 38 is that it automatically produces a fairlyconstant pressure drop regardless of output pressure settings. In analternate embodiment, a first pressure regulator (not shown) is providedin-line in input pressure line 30 before fluidizing pressure line 40 anda second pressure regulator (not shown) is provided in-line in inputpressure line 30 after fluidizing pressure line 40. The first and secondpressure regulators, however, must each be adjusted in response tooutput pressure setting changes to develop the desired pressure dropwithin input pressure line 30 for producing drive pressure forfluidizing pressure line 40.

[0031] Fluidizing pressure line 40 has a first end 42 and a second end44. First end 42 of fluidizing pressure line 40 communicates with aninput junction 36 provided in input pressure line 30 betweenlow-pressure check valve 37 and resister check valve 38. Second end 44of fluidizing pressure line 40 communicates with inlet valve 50. Assuch, fluidizing pressure line 40 provides a by-pass flow path which isin parallel flow with input pressure line 30 from input junction 36. Inone embodiment, a control valve 46 is provided in-line in fluidizingpressure line 40 before inlet valve 50. Control valve 46 is anadjustable valve used to set a desired flow rate, referred to as afluidizing flow rate, of pressurized air supplied to inlet valve 50. Anexample of such a control valve is a MNV-1K needle valve manufactured byClippard.

[0032] Inlet valve 50 communicates with fluidizing pressure line 40 onan input side 52 (FIG. 2) and inlet opening 26 of storage container 20on an output side 54 (FIG. 2). Inlet valve 50 has an opened state,illustrated in FIG. 2, and a closed state, illustrated in FIG. 3,depending on an operational state of pressurized delivery system 10.Inlet valve 50 is a one-way valve that permits substantially no flow inan upstream direction while permitting flow only in a downstreamdirection from fluidizing pressure line 40 to storage container 20. Inone embodiment, inlet valve 50 is made of a flexible material, forexample, rubber, and is commonly referred to as a flapper, or duckbill,check valve. The duckbill check valve is effective at creating a tightseal when closed despite communicating with abrasive particulatematerial 12. An example of such a check valve is a VL1490-102 checkvalve manufactured by Vernay Laboratories.

[0033] In an alternate embodiment, inlet valve 50 is a porous material(not shown) that permits air to flow from fluidizing pressure line 40 tostorage container 20, but does not permit abrasive particulate material12 to flow into fluidizing pressure line 40. The porous materialsuitably includes natural stones, micro-screen, filter cloth, or similarperforming material. An example of such a material is a macroporousmaterial formed of nylon and having a mesh opening of 8 micronsmanufactured by Spectrum.

[0034] Back-pressure pressure line 60 has a first end 62 and a secondend 64. First end 62 of back-pressure pressure line 60 communicates withunoccupied portion 22 b of interior space 22 of storage container 20.Second end 64 of back-pressure pressure line 60 communicates with outputjunction 76 of output pressure line 70. An inlet orifice 66 is providedat first end 62 of back-pressure pressure line 60 and has a diameterless than that of back-pressure pressure line 60. As such, inlet orifice66 restricts input of air into back-pressure pressure line 60 andreduces sensitivity of the system to differing levels of abrasiveparticulate material 12 contained within storage container 20. It istheorized that back-pressure created by inlet orifice 66 increases ahead on outlet opening 28 so that a head created by abrasive particulatematerial 12 itself is not the sole contributor to flow of abrasiveparticulate material 12 through outlet opening 28. Thus, variation offlow caused by differing levels of abrasive particulate material 12within storage container 20 is reduced.

[0035] Output pressure line 70 has a first end 72 and a second end 74.First end 72 of output pressure line 70 communicates with second end 34of input pressure line 30, second end 64 of back-pressure pressure line60, and outlet opening 28 of storage container 20 at output junction 76.An abrasive pinch 77 is provided in output pressure line 70 and a ventpinch 78 is provided in a vent tube 79 communicating with outputpressure line 70 before abrasive pinch 77. In addition, a nozzle 80 isprovided at second end 74 of output pressure line 70. Nozzle 80accelerates and directs abrasive particulate material 12 toward asurface to be processed. Abrasive pinch 77 and vent pinch 78 are usedduring operation of pressurized delivery system 10, as is known in theart.

[0036] In use, abrasive particulate material 12 is disposed withininterior space 22 of storage container 20 to a level such that first end64 of back-pressure pressure line 60 communicates with unoccupiedportion 22 b of interior space 22. In one illustrative embodiment,abrasive particulate material 12 is aluminum oxide. Pressurized air 14is regulated and supplied, by pressure regulating system 16, to firstend 32 of input pressure line 30, and first end 42 of fluidizingpressure line 40 after passing through low-pressure check valve 37. Tooperate pressurized delivery system 10, abrasive pinch 77 is opened, asillustrated in FIG. 1. Resister check valve 38, however, remains closeduntil a predetermined pressure differential, for example, 10 psi, occursacross resister check valve 38. This develops higher pressure beforeresister check valve 38 and produces drive pressure for fluidizingpressure line 40. When the predetermined pressure differential doesoccur across resister check valve 38, pressurized air 14 is releasedthrough resister check valve 38 and through filter 39 to output junction76.

[0037] During operation, control valve 46 is adjusted to establish adesired fluidizing flow rate of pressurized air 14 to inlet valve 50. Inone illustrative embodiment, with a standardized pressure of 4 psi, thefluidizing flow rate is adjusted to 6.0 standard cubic feet per hour(SCFH). The flow of pressurized air 14 causes inlet valve 50 to open, asillustrated in FIG. 2. As such, pressurized air 14, referred to as afluidizing air stream, is released into interior space 22 of storagecontainer 20, through inlet opening 26. Thereafter, baffle 25 disperses,or spreads out, pressurized air 14 released into interior space 22 ofstorage container 20 so as to more evenly distribute pressurized air 14throughout base 24 of storage container 20. Since outlet opening 28 isadjacent to inlet opening 26, abrasive particulate material 12 adjacentoutlet opening 28 is “fluidized.” Essentially, abrasive particulatematerial 12 adjacent outlet opening 28 develops a fluidic trait and, assuch, is maintained flowable through outlet opening 28. Thus, abrasiveparticulate material 12 is more accurately metered as it flowsconsistently through outlet opening 28 and to output junction 76 whereit joins pressurized air 14 released through resister check valve 38.

[0038] While abrasive particulate material 12 flows through outletopening 28, a portion of the fluidizing air stream released into storagecontainer 20 by inlet valve 50 is released through outlet opening 28 andto output junction 76 with abrasive particulate material 12. A portionof the fluidizing air stream released into storage container 20 by inletvalve 50 also permeates through abrasive particulate material 12 tounoccupied portion 22 b of interior space 22 where it is vented throughback-pressure pressure line 60 to output junction 76. As such, abrasiveparticulate material 12 and the portion of the fluidizing air streamreleased through outlet opening 28 with abrasive particulate material12, pressurized air 14 released through resister check valve 38, and theportion of the fluidizing air stream vented through back-pressurepressure line 60, come together at output junction 76 to form apressurized abrasive particulate material/air mixture 18. As such,pressurized abrasive particulate material/air mixture 18 is supplied tooutput pressure line 70. Thereafter, pressurized abrasive particulatematerial/air mixture 18 is accelerated through nozzle 80.

[0039] To discontinue operation, or develop a stand-by state, ofpressurized delivery system 10, abrasive pinch 77 is closed. Withabrasive pinch 77 closed, pressurized air 14 no longer flows throughpressurized delivery system 10. Inlet valve 50, therefore, returns tothe closed state, as illustrated in FIG. 3. Thus, a static mode ofpressurized delivery system 10 is established.

[0040] Referring to FIGS. 4-6, one illustrative application ofpressurized delivery system 10 is for forming an ink fill slot 122 in asilicon substrate 120 of an ink-jet printhead 100 for an ink-jet printer(not shown). FIG. 4 illustrates a portion of ink-jet printhead 100including a printing, or drop ejecting, element 110 formed on substrate120. Ink fill slot 122, formed in substrate 120, provides a supply ofink (not shown) to a plurality of printing elements 110 as illustratedin FIG. 5. Although FIG. 5 illustrates one common configuration of aplurality of printing elements 110 including two parallel rows ofprinting elements 110 along ink fill slot 122, other configurations ofprinting elements 110 employed in ink-jet printers, includingapproximately circular and single row configurations, are within thescope of the present invention.

[0041] As illustrated in FIG. 4, printing element 110 includes a layer112 having an ink feed channel 113 formed therein, a resistor 116positioned within ink feed channel 113, and a nozzle plate 118 having anozzle 119 formed therein. Ink feed channel 113 forms a drop ejectionchamber 115 surrounding resistor 116 on three sides. Ink (not shown) issupplied from ink fill slot 122 to drop ejection chamber 115 through apair of opposed projections 114 provided at an entrance to ink feedchannel 113. Nozzle 119 is operatively associated with resistor 116 suchthat droplets of ink are ejected through nozzle 119 (e.g., normal to theplane of resistor 116) and toward a print medium (not shown) uponheating of a quantity of ink by resistor 116. As such, alphanumericcharacters and graphics are formed on the print medium (not shown).

[0042] As illustrated in FIG. 6, substrate 120 has a first surface 124and a second surface 126 upon which printing element 110 is formed.Second surface 126 is opposed to and substantially parallel with firstsurface 124. In one embodiment, substrate 120 comprises a single crystalsilicon wafer, commonly used in the microelectronics industry. Inaddition, ink fill slot 122 communicates with both first surface 124 andsecond surface 126, and converges from first surface 124 toward secondsurface 126. As such, ink fill slot 122 provides a supply of ink (notshown) to second surface 126 and, therefore, printing element 110.

[0043] In accordance with the present invention, pressurized deliverysystem 10 is used to form ink fill slot 122 in silicon substrate 120 bydirecting a stream of pressurized abrasive particulate material/airmixture 18 at first surface 124 of silicon substrate 120. The stream ofpressurized abrasive particulate material/air mixture 18 is directed atfirst surface 124 at least until ink fill slot 122 communicates withsecond surface 126 of silicon substrate 120. Since ink fill slot 122provides the supply of ink to printing element 110 during the printingprocess, printing performance depends on uniformity of ink fill slot122. A distance from an edge of ink fill slot 122 to drop ejectionchamber 115, for example, determines how rapidly drop ejection chamber115 can refill with ink after ink is ejected from drop ejection chamber115 during the printing process. How rapidly drop ejection chamber 115can refill with ink, in turn, effects a frequency of operation ofprinting element 110 and, therefore, printing speed. Compared withexisting sandblasting systems employed for forming ink fill slot 122,pressurized delivery system 10 has been shown to significantly reducesize and shape variations of ink fill slot 122.

[0044] While pressurized delivery system 10 has been described andillustrated for use in forming ink fill slot 122 in silicon substrate120 of ink-jet printhead 100 with pressurized abrasive particulatematerial/air mixture 18, it is apparent that pressurized delivery system10 is useful for other cleaning, polishing, abrading or relatedoperations. Other example embodiments of pressurized delivery system 10are employed for removing paint, rust, or other foreign materials fromsurfaces including metal, concrete, or the like, cleaning or polishingjewelry or corroded articles, and/or abrading or polishing steel orother metal components.

[0045] Fluidizing pressure line 40 supplies pressurized air 14 tostorage container 20 so as to fluidize a quantity of abrasiveparticulate material 12 contained therein. As such, abrasive particulatematerial 12 flows consistently through outlet opening 28 of storagecontainer 20 to join pressurized air 14 supplied to output pressure line70. Pressurized delivery system 10, therefore, provides a system fordelivering abrasive particulate material under pressure such that moreaccurately metered flow of the abrasive particulate material from astorage container, through a metering orifice, and into an outputpressure line is achieved.

[0046] Although specific embodiments have been illustrated and describedherein for purposes of description of the preferred embodiment, it willbe appreciated by those of ordinary skill in the art that a wide varietyof alternate and/or equivalent implementations calculated to achieve thesame purposes may be substituted for the specific embodiments shown anddescribed without departing from the scope of the present invention.Those with skill in the chemical, mechanical, electromechanical,electrical, and computer arts will readily appreciate that the presentinvention may be implemented in a very wide variety of embodiments. Thisapplication is intended to cover any adaptations or variations of thepreferred embodiments discussed herein. Therefore, it is manifestlyintended that this invention be limited only by the claims and theequivalents thereof.

What is claimed is:
 1. A pressurized delivery system for abrasiveparticulate material, the pressurized delivery system comprising: astorage container defining an interior space adapted to contain theabrasive particulate material therein, the storage container including abase having an inlet opening and an outlet opening defined therein; aninlet valve communicating with the inlet opening; a first flow pathcommunicating with the inlet valve; a second flow path communicatingwith the first flow path and adapted to communicate with a pressurizedsource of gas; a third flow path communicating with the second flowpath; a fourth flow path communicating with an unoccupied portion of theinterior space of the storage container; and a fifth flow pathcommunicating with the third flow path, the outlet opening, and thefourth flow path.
 2. The pressurized delivery system of claim 1, whereinthe third flow path is in parallel flow with the first flow path fromthe second flow path.
 3. The pressurized delivery system of claim 1,wherein the abrasive particulate material includes at least one of sand,aluminum oxide, silicon carbide, quartz, and diamond dust.
 4. Thepressurized delivery system of claim 1, wherein the gas is air.
 5. Thepressurized delivery system of claim 1, wherein the gas is an inert gas.6. The pressurized delivery system of claim 1, wherein the inlet valveis a one-way valve.
 7. The pressurized delivery system of claim 6,wherein the one-way valve is a duckbill check valve.
 8. The pressurizeddelivery system of claim 1, further comprising: an adjustable controlvalve provided in-line in the first flow path before the inlet valve. 9.The pressurized delivery system of claim 1, further comprising: a firstcheck valve provided in-line in the second flow path before the firstflow path and the third flow path; and a second check valve providedin-line in the third flow path.
 10. The pressurized delivery system ofclaim 9, further comprising: a filter provided in-line in the third flowpath after the second check valve.
 11. The pressurized delivery systemof claim 1, wherein the fourth flow path includes an inlet orificecommunicating with the unoccupied portion of the interior space of thestorage container, the inlet orifice restricting input to the fourthflow path.
 12. The pressurized delivery system of claim 1, furthercomprising: a baffle positioned within the storage container above theinlet opening.
 13. The pressurized delivery system of claim 1, furthercomprising: a nozzle provided at an output end of the fifth flow path.14. A pressurized delivery system for abrasive particulate material, thepressurized delivery system comprising: an input pressure line having afirst end and a second end, the first end adapted to communicate with apressurized source of gas; a fluidizing pressure line having a first endand a second end, the first end of the fluidizing pressure linecommunicating with the input pressure line intermediate the first andsecond ends of the input pressure line; an inlet valve communicatingwith the second end of the fluidizing pressure line; a storage containerdefining an interior space adapted to contain the abrasive particulatematerial therein, the storage container including a base having an inletopening and an outlet opening defined therein, the inlet openingcommunicating with the inlet valve; a back-pressure pressure line havinga first end and a second end, the first end of the back-pressurepressure line communicating with an unoccupied portion of the interiorspace of the storage container; and an output pressure line having afirst end and a second end, the first end of the output pressure linecommunicating with the second end of the input pressure line, the secondend of the back-pressure pressure line, and the outlet opening of thestorage container.
 15. The pressurized delivery system of claim 14,wherein a portion of the input pressure line is in parallel flow withthe fluidizing pressure line.
 16. The pressurized delivery system ofclaim 14, wherein the abrasive particulate material includes at leastone of sand, aluminum oxide, silicon carbide, quartz, and diamond dust.17. The pressurized delivery system of claim 14, wherein the gas is air.18. The pressurized delivery system of claim 14, wherein the gas is aninert gas.
 19. The pressurized delivery system of claim 14, wherein theinlet valve is a one-way valve.
 20. The pressurized delivery system ofclaim 19, wherein the one-way valve is a duckbill check valve.
 21. Thepressurized delivery system of claim 14, further comprising: anadjustable control valve provided in-line in the fluidizing pressureline before the inlet valve.
 22. The pressurized delivery system ofclaim 14, further comprising: a first check valve provided in-line inthe input pressure line before the fluidizing pressure line; and asecond check valve provided in-line in the input pressure line after thefluidizing pressure line.
 23. The pressurized delivery system of claim22, further comprising: a filter provided in-line in the input pressureline after the second check valve.
 24. The pressurized delivery systemof claim 14, wherein the back-pressure pressure line includes an inletorifice communicating with the unoccupied portion of the interior spaceof the storage container, the inlet orifice restricting input to theback-pressure pressure line.
 25. The pressurized delivery system ofclaim 14, further comprising: a baffle positioned within the storagecontainer above the inlet opening.
 26. The pressurized delivery systemof claim 14, further comprising: a nozzle provided at the second end ofthe output pressure line.
 27. A method of delivering abrasiveparticulate material from a storage container adapted to contain theabrasive particulate material therein, the storage container including abase having an inlet opening and an outlet opening defined therein, themethod comprising the steps of: disposing the abrasive particulatematerial within the storage container; communicating an inlet valve withthe inlet opening; supplying a first gas regulated to a firstpredetermined pressure to the inlet valve and releasing the first gasthrough the inlet valve and into the storage container; discharging aquantity of the abrasive particulate material through the outlet openingand to an output junction; and supplying a second gas regulated to asecond predetermined pressure to the output junction.
 28. The method ofclaim 27, wherein the abrasive particulate material includes at leastone of sand, aluminum oxide, silicon carbide, quartz, and diamond dust.29. The method of claim 27, wherein the first gas is air.
 30. The methodof claim 27, wherein the first gas is an inert gas.
 31. The method ofclaim 27, wherein the second gas is air.
 32. The method of claim 27,wherein the second gas is an inert gas.
 33. The method of claim 27,wherein the first gas and the second gas are the same type of gas. 34.The method of claim 33, wherein the first gas and the second gas areair.
 35. The method of claim 33, wherein the first gas and the secondgas are an inert gas.
 36. The method of claim 27, wherein the inletvalve is a one-way valve.
 37. The method of claim 36, wherein theone-way valve is a duckbill check valve.
 38. The method of claim 27,wherein the step of supplying the first gas further includes adjustablycontrolling the first gas.
 39. The method of claim 27, wherein the stepof supplying the first gas further includes dispersing the first gas.40. The method of claim 27, wherein the step of supplying the first gasfurther includes fluidizing a quantity of the abrasive particulatematerial within the storage container adjacent the outlet opening. 41.The method of claim 27, wherein the step of supplying the second gasfurther includes filtering the second gas.
 42. The method of claim 27,further comprising the step of: venting a portion of the first gas tothe output junction.
 43. The method of claim 27, further comprising thestep of: communicating the output junction with an output nozzle.
 44. Amethod of abrading a portion of a silicon substrate, the methodcomprising the steps of: fluidizing abrasive particulate material with afirst gas within a storage container; combining the gas fluidizedabrasive particulate material with a stream of a second gas to provide astream of the gas fluidized abrasive particulate material; and directingthe stream of the gas fluidized abrasive particulate material at thesilicon substrate to abrade the portion of the silicon substrate. 45.The method of claim 44, wherein the abrasive particulate materialincludes at least one of sand, aluminum oxide, silicon carbide, quartz,and diamond dust.
 46. The method of claim 44, wherein the first gas isair.
 47. The method of claim 44, wherein the first gas is an inert gas.48. The method of claim 44, wherein the second gas is air.
 49. Themethod of claim 44, wherein the second gas is an inert gas.
 50. Themethod of claim 44, wherein the first gas and the second gas are thesame type of gas.
 51. The method of claim 50, wherein the first gas andthe second gas are air.
 52. The method of claim 50, wherein the firstgas and the second gas are an inert gas.
 53. The method of claim 44,wherein the step of directing the stream of the gas fluidized abrasiveparticulate material at the silicon substrate includes forming a slot inthe silicon substrate.
 54. A method of forming an ink fill slot in asilicon substrate of an ink-jet printhead, the method comprising thesteps of: fluidizing abrasive particulate material with a first gaswithin a storage container; combining the gas fluidized abrasiveparticulate material with a stream of a second gas to provide a streamof the gas fluidized abrasive particulate material; and directing thestream of the gas fluidized abrasive particulate material at the siliconsubstrate to form the ink fill slot in the silicon substrate.
 55. Themethod of claim 54, wherein the abrasive particulate material includesat least one of sand, aluminum oxide, silicon carbide, quartz, anddiamond dust.
 56. The method of claim 54, wherein the first gas is air.57. The method of claim 54, wherein the first gas is an inert gas. 58.The method of claim 54, wherein the second gas is air.
 59. The method ofclaim 54, wherein the second gas is an inert gas.
 60. The method ofclaim 54, wherein the first gas and the second gas are the same type ofgas.
 61. The method of claim 60, wherein the first gas and the secondgas are air.
 62. The method of claim 60, wherein the first gas and thesecond gas are an inert gas.
 63. The method of claim 54, wherein thesilicon substrate has a first surface and a second surface opposed toand substantially parallel with the first surface.
 64. The method ofclaim 63, wherein the step of directing the stream of the gas fluidizedabrasive particulate material at the silicon substrate includesdirecting the stream of the gas fluidized abrasive particulate materialat the first surface of the silicon substrate to form the ink fill slotin the silicon substrate.
 65. The method of claim 64, wherein the stepof directing the stream of the gas fluidized abrasive particulatematerial at the first surface of the silicon substrate includesdirecting the stream of the gas fluidized abrasive particulate materialat the first surface at least until the ink fill slot communicates withthe second surface of the silicon substrate.
 66. An ink-jet printhead,comprising: a silicon substrate having an ink fill slot formed thereinby: fluidizing abrasive particulate material with a first gas within astorage container, combining the gas fluidized abrasive particulatematerial with a stream of a second gas to provide a stream of the gasfluidized abrasive particulate material, and directing the stream of thegas fluidized abrasive particulate material at the silicon substrate toform the ink fill slot in the silicon substrate.
 67. The ink-jetprinthead of claim 66, wherein the abrasive particulate materialincludes at least one of sand, aluminum oxide, silicon carbide, quartz,and diamond dust.
 68. The ink-jet printhead of claim 66, wherein thefirst gas is air.
 69. The ink-jet printhead of claim 66, wherein thefirst gas is an inert gas.
 70. The ink-jet printhead of claim 66,wherein the second gas is air.
 71. The ink-jet printhead of claim 66,wherein the second gas is an inert gas.
 72. The ink-jet printhead ofclaim 66, wherein the first gas and the second gas are the same type ofgas.
 73. The ink-jet printhead of claim 72, wherein the first gas andthe second gas are air.
 74. The ink-jet printhead of claim 72, whereinthe first gas and the second gas are an inert gas.
 75. The ink-jetprinthead of claim 66, wherein the silicon substrate has a first surfaceand a second surface opposed to and substantially parallel with thefirst surface.
 76. The ink-jet printhead of claim 75, wherein the stepof directing the stream of the gas fluidized abrasive particulatematerial at the silicon substrate includes directing the stream of thegas fluidized abrasive particulate material at the first surface of thesilicon substrate.
 77. The ink-jet printhead of claim 76, wherein thestep of directing the pressurized stream of the gas fluidized abrasiveparticulate material at the first surface of the silicon substrateincludes directing the pressurized stream of the gas fluidized abrasiveparticulate material at the first surface at least until the ink fillslot communicates with the second surface of the silicon substrate. 78.The ink-jet printhead of claim 75, wherein the ink fill slotcommunicates with the first surface and the second surface.
 79. Theink-jet printhead of claim 75, wherein the ink fill slot converges fromthe first surface toward the second surface.
 80. The ink-jet printheadof claim 75, further comprising: at least one printing element formed onthe second surface of the silicon substrate, the ink fill slot beingadapted to provide a supply of ink to the at least one printing element.